At machines provided with belt drives with one or more V-belts/belts (in the description below termed belt) between a motor with or without transmission (in the description below termed engine/transmission) and a driven shaft/driven shafts (in the description below termed driven shaft) of a machine a tensioning device for tensioning the belt is used.
More particularly, the belt tension is normally adjusted by a force being applied between the engine/transmission having a driving pulley and a driven pulley of a machine, and at adequate belt tension the distance between the pulleys relative to each other is locked by a threaded locking device, for instance.
Today, the belt tension is adjusted at most belt drives by means of threaded elements, threaded rods and adjusting nuts, for instance, which are rotated when the belt tension is increase/decrease, whereupon the setting is fixed by a locking nut. For this adjustment a tool and a measuring instrument is needed to verify the belt tension every time the belt is change/adjusted.
A disadvantage, when threaded elements are used to obtain the belt tension, is that with this typically means at least two points of adjustments have to be adjusted. With this method, the alignment must be done with the instrument each time the belt tension is released. This is not always done in practice.
A further disadvantage is that after a period of time the threads are usually damaged due to corrosion and/or mechanically, which means that it is not possible to reduce/increase the tension of the belt without replacing the damaged threaded elements.
Replacement of threaded elements is an additional maintenance cost and in many cases this means a long downtime of the machine, and it is not unusual with loss of production as a result.
To minimize loss of production, it sometimes happens that the belt is replaced by tools in a non-proper way which may damage the belt and reduce the useful life of the belt. One way is to force the belt by a tool onto the pulleys by extending it too much so as to mount the belt onto the pulleys. Then there is a risk of losing the control of the belt tension and the alignment.
Wrong belt tension and non-aligned pulleys means that the belt drive runs with unnecessarily high energy consumption and poor efficiency and the useful life of the belt is shortened.